1. Field of the Invention
The present invention relates to an image reading apparatus, and particularly to an image reading apparatus in which an image recorded on an original to be read such as a photographic film is read based on light transmitted through the image or light reflected from the image.
2. Description of the Related Art
There has been proposed in recent years a photographic processing method in which a film image recorded on a photosensitive material such as a photographic film (hereinafter referred to merely as photographic film) is read by an image sensor such as a CCD, based on light transmitted through the film image or light reflected from the film image when light is irradiated on the film image, and image data obtained by the reading is subjected to image processings including various corrections, and thereafter, the image is recorded on a recording material or is displayed on a display. It should be noted that the term photographic film used here refers to a film whose negative image or positive image is visualized by development processing, after a subject has been photographed.
In an image reading apparatus for use in reading a film image in this type of photographic processing method, a diffusion box is widely used in which illumination light emitted from a light source is made into diffused light, with the objects of making the amount of light, which is irradiated on the film image, substantially uniform, and making scratches, which are formed on the film surface when the image is recorded on a recording material, difficult to see. (See Japanese Patent Application Laid-Open (JP-A) Nos. 9-114008, 8-76271, etc.)
Conventionally, when a plurality of types of photographic film are to be read by the image reading apparatus as described above, such a diffusion box has been provided in advance for each type of photographic film, and an operator chooses the diffusion box according to the type of the photographic film to be read and disposes the chosen diffusion box at a predetermined position.
In other words, since the size of a film image recorded on a photographic film varies depending on the type of photographic film, there is a need to change an illumination range according to the type of the photographic film. Thus, there is a need to pick out and use the proper diffusion box from among several diffusion boxes according to the illumination range. In this case, a structure has also been conceived of in which a common diffusion box is used that can illuminate the entire surface of the largest film image of the film images recorded on the photographic films to be read by the image reading apparatus. However, it is desirable to irradiate an amount of light which is as large as possible on a photographic film by using a low amount of energy. Therefore, from this standpoint, it is preferable to employ a structure in which a proper diffusion box is picked out for use, from among several diffusion boxes, for each type of photographic film (for each size of photographic film).
However, in the above-described technique in which a proper diffusion box is picked out and used, from among several diffusion boxes, for each type of photographic film to be read, there is a problem in that, as the operator chooses the diffusion box according to type of the photographic film to be read and disposes it at a predetermined position, a large responsibility is imposed upon the operator and he/she may choose a wrong diffusion box.
The present invention has been attained to solve the above-described problems, and an object thereof is to provide an image reading apparatus in which the responsibility imposed upon an operator can be reduced and a wrong diffusion box can be prevented from being mischosen.
In order to achieve the above-described object, according to a first aspect of the present invention, there is provided an image reading apparatus comprising: illuminating means for illuminating an original to be read; changing means for changing automatically one of an illumination range and a degree of diffusion of the illuminating means according to reading conditions of the original to be read; a lens for focussing the original to be read; and an image sensor for separating the image of the original to be read, which is obtained through the lens, into a plurality of pixels for reading and outputting as image data.
In the image reading apparatus of the first aspect of the present invention, an original to be read is illuminated by the illuminating means. At this time, the changing means causes one of an illumination range and a degree of diffusion of the illuminating means to be changed automatically according to reading conditions of the original to be read. It should be noted that the above original to be read includes a transparent original such as a photographic film, a reflective original such as a photographic print, and the like.
Subsequently, an image of the original to be read, which is obtained through the lens for focusing the original to be read, is separated into a plurality of pixels and read by an image sensor, and is then outputted as image data. It should be noted that the above image sensor includes a linear CCD, an area CCD, and photoelectric transfer elements other than a CCD.
As described above, in the image reading apparatus of the first aspect of the present invention, since one of the illumination range and the degree of diffusion of the illuminating means are changed automatically according to the reading conditions of the original to be read, compared with the case in which the illumination range and degree of diffusion are changed by an operator, the responsibility imposed upon the operator can be reduced.
It should be noted that the above reading conditions of the first aspect include, as the second aspect, the following three types:
The size of the original to be read.
Whether the reading to be carried out is a preliminary reading or a main reading when the reading is carried out in two steps, i.e., the preliminary reading for reading an original to be read at relatively high speed but with low precision and the main reading for reading the original to be read at relatively low speed but with high precision based on image data obtained by the preliminary reading.
Whether the printing is a simultaneous film processing or a reprinting when the original to be read is a photosensitive material (photographic film).
In other words, generally, the larger the size of the original to be read is, the broader the area to be read becomes. Accordingly, as the size of the original to be read becomes larger, the range illuminated by the illuminating means is automatically broadened.
Further, when the original to be read is read in two steps, i.e., by the preliminary reading and the main reading, an area to be read sometimes needs to be broadened when the preliminary reading is carried out, compared with when the main reading is carried out. For example, if the original to be read is a photographic film, it is often necessary to detect the position of perforations as well as the contents of a bar code, which are provided outside the film image of the photographic film, when the preliminary reading is carried out. In such a case, the illumination range is automatically broadened when the preliminary reading is carried out, compared with when the main reading is carried out. As a result, an appropriate illumination range corresponding to the reading conditions (whether it is the preliminary reading or the main reading) can be automatically set.
Moreover, there are also occasions when scratches on the photographic film are present when the original to be read is a photographic film and reprints are made thereof. Therefore, the degree of diffusion of the illumination light is increased at the time of reprinting, compared with during simultaneous film processing, in order to reduce the scratches appearing on the print. Conversely, during simultaneous film processing, because there are hardly any scratches on the photographic film, the degree of diffusion is decreased thus allowing increased processing performance.
Likewise, examples of applicable methods, in which the illumination range and the degree of diffusion are changed automatically by the changing means in the first aspect, include a method in which the means for changing an area of an illumination light emitted from the illumination means is provided at an illumination light emitting side of the illuminating means so that the change is carried out by the means, as well as a method in which when the illuminating means is comprised of a plurality of light emitting portions disposed linearly or in the form of an array (in two dimensions), the illumination range is changed by turning on, among the above plurality of light emitting portions, only the ones that correspond to the area to be illuminated.
When the original to be read is, for example, a photographic film, as mentioned above, the size of the film image recorded on the photographic film differs depending on the type of photographic film. Accordingly, there is a need to change the illumination range and the degree of diffusion according to the type of photographic film.
Thus, according to a third aspect of the present invention, there is provided an image reading apparatus according to the first or second aspect, wherein the changing means is comprised of: a plurality of light diffusing means, each of which having one of a different illumination range and a degree of diffusion, in which illumination light generated by the illuminating means is made into diffused light; and controlling means for changing one of the illumination range and the degree of diffusion automatically by effecting control such that the light diffusing means corresponding to the type of the original to be read is chosen from among the plurality of light diffusing means and the chosen light diffusing means is located on one of an optical axis and an optical path.
In the image reading apparatus of the third aspect of the present invention, one of the illumination range and the degree of diffusion is changed automatically when the controlling means effects control such that light diffusing means corresponding to the type of an original to be read is chosen, from among a plurality of light diffusing means in which illumination light generated by the illuminating means is made into diffused light and each of which has one of a different illumination range and degree of diffusion, and the chosen light diffusing means is located on one of an optical axis and an optical path. It should be noted that the above-described diffusion box corresponds to the light diffusing means of the present invention.
As described above, in the image reading apparatus of the third aspect of the present invention, one of the illumination range and the degree of diffusion is changed automatically by choosing the light diffusing means in accordance with the type of the original to be read from among the plurality of light diffusing means, in which the illumination light generated by the illuminating means is made into diffused light and each of which has one of a different illumination range and degree of diffusion, and by locating the chosen light diffusing means on one of the optical axis and the optical path. Accordingly, the responsibility imposed upon an operator can be reduced and errors in setting the light diffusing means (such as a mischoice of the light diffusing means, an error in the setting procedure of the light diffusing means, and the like) can be prevented, compared with the case in which light diffusing means has been provided for each type of original to be read and the operator chooses and sets the light diffusing means according to the type of the original to be read.
According to a fourth aspect of the present invention, there is provided an image reading apparatus according to the third aspect, further comprising a plurality of conveying means, each of which is provided for each type of original to be read, for conveying the original to be read in such a manner that the original to be read passes a position at which the image sensor carries out a reading, wherein the controlling means chooses the light diffusing means in accordance with the type of the original to be read by detecting the type of the original to be read or the type of the conveying means.
As described above, when the image reading apparatus of the third aspect of the present invention includes the plurality of conveying means, each of which is provided for each type of original to be read, for conveying the original to be read in such a manner that the original to be read passes a position in which the image sensor carries out a reading, the type of the original to be read, which has been described above, can be specified not only by detecting directly the type of the original to be read but also by detecting the type of the conveying means.
In a fifth aspect of the present invention, in the image reading apparatus according to the third or fourth aspect, the controlling means can cause the chosen light diffusing means to move, thereby allowing it to be located on one of the optical axis and the optical path. The movement here includes a movement in which the plurality of light diffusing means are integrated into a single structure or unit and the chosen light diffusing means is located on one of the optical axis and optical path by moving the integrated structure, and a movement in which the chosen light diffusing means is located on one of the optical axis and optical path by moving the chosen light diffusing means individually.
According to a sixth aspect of the present invention, there is provided an image reading apparatus according to the first or second aspect, wherein the changing means is comprised of: a light diffusing means whose outer periphery is structured in the form of a hollow cylinder with four side walls comprising a pair of first side walls and a pair of second side walls whose respective upper end portions are movable toward and apart from each other, and which makes illumination light generated by the illuminating means into diffused light; and controlling means for changing the illumination range automatically by effecting control so that the respective upper end portions of the second side walls are moved according to the type of the original to be read.
In the image reading apparatus of the sixth aspect of the present invention, the outer periphery of the light diffusing means is structured in the form of a hollow cylinder with four side walls comprising a pair of first side walls and a pair of second side walls whose upper end portions are movable toward and apart from each other, and the illumination range is changed automatically by moving upper end portions of the second side walls of the light diffusing means, in which illumination light generated by the illuminating means is made into diffused light, according to the type of original to be read.
As described above, in the image reading apparatus of the sixth aspect of the present invention, the outer periphery of the light diffusing means is structured in the form of a hollow cylinder with four side walls comprising a pair of first side walls and a pair of second side walls whose upper end portions are movable toward and apart from each other, and the illumination range is changed automatically by moving upper end portions of the second side walls of the light diffusing means, in which illumination light generated by the illuminating means is made into diffused light, according to the type of original to be read. Accordingly, it is made possible to accommodate a plurality of types of originals to be read with one light diffusing means. Also, as compared with the case in which light diffusing means is provided for each type of original to be read, the region for installing the light diffusing means can be made smaller, which allows miniaturization of the apparatus as well as a reduction in the cost of the apparatus.
According to a seventh aspect of the present invention, there is provided an image reading apparatus according to the sixth aspect, wherein the pair of first side walls is structured in such a manner that the respective upper end portions thereof are able to move toward and apart from each other, and the controlling means effects control so that the respective upper end portions of the pair of first side walls are moved in the direction in which they move apart from each other before the second side walls are moved, and the respective upper end portions of the pair of first side walls are moved in the direction in which they move toward each other after the second side walls has been moved.
In the image reading apparatus of the seventh aspect of the present invention, in the image reading apparatus of the sixth aspect, the pair of first side walls are structured in such a manner that the respective upper end portions thereof are able to move toward and apart from each other, and further the controlling means causes the respective upper end portions of the pair of first side walls to move in the direction in which they move apart from each other before the second side walls are moved, and the respective upper end portions of the pair of first side walls to move in the direction in which they move toward each other after the second side walls has been moved.
As described above, in the image reading apparatus of the seventh aspect of the present invention, an effect similar to that of the invention of the sixth aspect can be realized. In addition, since the respective upper end portions of the pair of first side walls are moved in the, direction in which they move apart from each other before the second side walls are moved, and the respective upper end portions of the pair of first side walls are moved in the direction in which they move toward each other after the second side walls has been moved, the second side walls do not come into contact with the first side walls when the second side walls are moved. Accordingly, the second side walls can be moved by using a low amount of energy and damage caused by the friction of the respective side walls can be prevented.
It should be noted in the image reading apparatus of the sixth and seventh embodiments, movement of the pair of second side walls is preferably carried out in a continuous manner or a stepping manner. When the second side walls are moved in the continuous manner, the upper end portions thereof can be set at any position insofar as it is within a region allowed for movement. Thus, the structure can be used for a larger number of types of originals to be read, compared with the case in which the second side walls are moved in the stepping manner. When the pair of second side walls is moved in the stepping manner, compared with the case in which they are moved in the continuous manner, more accurate positioning thereof can be conducted in a shorter time.
According to an eighth aspect of the present invention, there is provided an image reading apparatus for irradiating light outputted from a light source onto an original so as to read light transmitted through the original or light reflected by the original by a photoelectric transfer element, comprising: a plurality of diffusion boxes for converting the light outputted from the light source into diffused light so as to irradiate the diffused light onto an area of the original to be read; and moving means for selectively moving the plurality of diffusion boxes on an optical path of the light outputted from the light source.
In the image reading apparatus of the eighth aspect of the present invention, the plurality of diffusion boxes convert the light outputted from the light source into diffused light. For example, a plurality of diffusion boxes that have different light irradiation areas can be used so as to irradiate the light from the light source onto the originals of different original sizes. Further, the moving means selectively moves the plurality of diffusion boxes on the optical path of the light outputted from the light source. In other words, diffused light can be irradiated onto the light irradiation area in accordance with the reading conditions such as the size of the original and the like. Accordingly, although the necessity for an operator to change the diffusion boxes according to the reading conditions such as the size of the original and the like is obviated, efficient reading of the image can be carried out.
According to a ninth aspect of the present invention, there is provided an image reading apparatus for irradiating light outputted from a light source onto an original so as to read light transmitted through the original or light reflected by the original by a photoelectric transfer element, comprising: a first diffusion box for converting the light outputted from the light source into diffused light so as to irradiate the diffused light onto an area of the original to be read; and a second diffusion box for converting the light outputted from the light source into diffused light so as to irradiate the diffused light onto the original to be read, which is disposed in such a manner as to be movable with the light source inside the first diffusion box along the optical axis of the light outputted from the light source.
In the image reading apparatus of the ninth aspect of the present invention, the first diffusion box, for example, makes the light from the light source into diffused light such that the light is irradiated on the original of the largest size of all the originals to be read. Then, the second diffusion box is provided in the interior of the first diffusion box and is disposed in such a manner as to be movable with the light source along the optical axis of the light outputted from the light source. In other words, by moving the positions of the light source and the second diffusion box along the optical axis of the light outputted from the light source, originals of different sizes, i.e., originals from the smallest to the largest sizes of all the originals to be read, can be read. Moreover, as the light source is moved with the second diffusion box, efficient use of the light outputted from the light source can be achieved.
Accordingly, although the necessity for an operator to change the diffusion boxes according to the reading conditions such as the size of the original and the like is obviated, efficient reading of the image can be carried out.
For example, when a 220 size (Brownie size) photographic film and a 135 size photographic film are read as originals, the range onto which the diffusion light according to the size of the photographic film (the size of the original) is irradiated is adjusted in the following manner: the second diffusion box is moved in the direction in which it moves away from the photographic film so that the Brownie size photographic film can be read by the first diffusion box, and for the reading of the 135 size photographic film, the second diffusion box is moved in the direction in which it moves toward the photographic film so that the 135 size photographic film is read by the second diffusion box.
An LED element can be used as the light source.